Engine-mounted autonomous flying device

ABSTRACT

An autonomous flying device achieving a large payload and a long continuous flight tune and also accurately adjust position and orientation while flying. The device includes: a main rotor and the like that provide main thrust; a sub rotor and the like that controls the orientation; an engine that generates energy for rotating the main rotor and the like and the sub rotor and the like; and an arithmetic control device that controls rotation of the sub rotor and the like. Also, the main rotor and the like are rotated by being drivingly connected to the engine, whereas the sub rotor and the like are rotated by motors driven by electric power generated from generator and the like operated by the engine. Further, when orientation control to tilt the fuselage is performed, the arithmetic control device increases the output distribution ratio of the sub rotor to above the output distribution ratio of the sub rotor when hovering is performed.

TECHNICAL FIELD

The present invention relates to an engine-mounted autonomous flyingdevice and relates in particular to a so-called hybrid engine-mountedautonomous flying device that drivingly drives main rotors with anengine and rotates sub rotors with electric power obtained fromgenerators driven by the engine.

BACKGROUND ART

Autonomous flying devices have heretofore been known which are capableof unmanned flight in the air. These autonomous flying devices arecapable of flying in the air by using thrust from rotors rotating aboutvertical axes.

Possible application fields of such autonomous flying devices include,for example, the fields of transportation, surveying, photo/videoshooting, and so on. In the case of using an autonomous flying device insuch a field, the flying device is equipped with a surveying device oran image capturing device. By using a flying device is used in such afield, it is possible to cause the flying device to fly over an area.where humans cannot enter, and transport an article to, shoot a photo orvideo of, or survey that area. Inventions related to such autonomousflying devices are disclosed in Patent Literatures 1 and 2, for example.

A general autonomous flying device rotates the above-mentioned rotorswith electric power supplied from a rechargeable battery mounted on theflying device. However, the supply of electric power from therechargeable battery does not always provide a sufficient amount ofenergy supply. in view of this, autonomous flying devices have emergedon which an engine is mounted to achieve a continuous flight over a longperiod of time. Such an autonomous flying device rotates generators withdriving force from the engine, and rotationally drives the rotors withelectric power generated by the generators. An autonomous flying devicewith such a configuration is called a series type drone since the engineand the generators are connected in series on the paths through which tosupply energy to the rotors from the mechanical power source. By performphoto/video shooting or surveying with such an autonomous flying device,it is possible to perform photo/video shooting or surveying over a vastarea. An engine-mounted flying device is disclosed in Patent Literature3, for example.

CITATION LIST Patent Literatures

-   [Patent Literature 1] Japanese Patent Application Publication No.    2012-51545-   [Patent Literature 2] Japanese Patent: pplication Publication No.    2014-240242-   [Patent Literature 3] Japanese Patent Application Publication No.    2011-251678

SUMMARY OF INVENTION Technical Problems

Considering the current situation with the expanding use of autonomousflying devices, autonomous flying devices are required to increase theirloadable package weight, that is, to increase their payload. Further,autonomous flying devices are also required to fly continuously over along period of time, in order to fly a long distance.

However, battery-driven autonomous flying devices having only arechargeable battery as the driving energy source for their rotors havea problem of small payload and short continuous flight time since theenergy obtained from the battery is not so large. For example, thepayload of a battery-driven autonomous flying device is about 10 kg, andits continuous flight time is about 20 minutes.

Meanwhile, a series type autonomous flying device, which rotates itsrotors by using el.ectnc power generated with an engine, can achieve arelatively large payload and a relatively long continuous flight timesince the driving source is the engine For example, the payload of a.series type autonomous flying device is about 20 kg, and its continuousflight time is about one hour. However, in a series type autonomousflying device, the energy to be transmitted to its rotors passes from anengine through generators. power conditioners, and motors. This resultsin an energy loss corresponding to the efficiency of the generators andthe power conditioners. Thus, series type autonomous flying devices havea problem in that the energy efficiency as a whole is not high and thusit is not easy to increase the payload.

Further, hybrid autonomous flying, devices have been developed Which areautonomous flying devices including engine-driven rotors andmotor-driven rotors. It is, however, not easy to change the orientationof an autonomous flying device 10 and do the like in a. stable mannerwhile enhancing the operation efficiency.

The present invention has been made in view of the above circumstances,and an object thereof is to provide an autonomous living device capableof achieving a large payload and a long continuous flight time and alsoaccurately adjusting its position and orientation while flying.

Solution to Problems

An engine-mounted autonomous flying device according to the presentinvention includes: a main rotor that gives main thrust to a fuselage; asub rotor that controls orientation of the fuselage; an engine thatgenerates energy for rotating the main rotor and the sub rotor; and anarithmetic control device that controls rotation of the sub rotor, andthe main rotor is rotated by being drivingly connected to the engine,the sub rotor is rotated by a motor driven by electric power generatedfrom a generator operated by the engine, and when orientation control totilt the fuselage is performed. the arithmetic control device increasesan output distribution ratio of the sub rotor to above an outputdistribution ratio of the sub rotor when hovering is performed.

Also, in engine-mounted autonomous flying device according to thepresent invention, the engine-mounted autonomous flying device accordingto claim 1, wherein the arithmetic control device sets the outputdistribution ratio of the sub rotor at 10% or more and 30% or less whenthe orientation control is performed.

Also, the engine-mounted autonomous flying device according to thepresent invention further includes: an electric power converter thatconverts the electric power generated from the generator; and a.capacitor that stores electric power outputted from the electric powerconverter, and the arthmetic control device charges the capacitor whenthe hovering, is performed, and supplies electric power discharged bythe capacitor to the motor when the orientation control is performed.

Also, in the engine-mounted autonomous flying device according to thepresent invention, a rotational speed of the engine when the hovering isperformed and a rotational speed of the engine when the orientationcontrol is performed are substantially same.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the engine and the main rotor are drivingly connectedvia a belt.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the engine has a. first engine part having a firstpiston that reciprocates and a second engine part having a second pistonthat reciprocates while facing the first piston.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the first piston and the second piston reciprocateinside a continuous cylinder.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the first piston reciprocates inside a firstcylinder, and the second piston reciprocates inside a second cylinderformed as a separate body from the first cylinder.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the sub rotor is attached to a. tip side of a sub armextending outward from a portion where the engine is arranged, and themain rotor is attached to a tip side of a main arm being longer than thesub arm arnd extending outward from the portion where the engine isarranged.

Also, in the engine-mounted autonomous flying device according to thepresent invention, driving force is transmitted to the main rotor via anengine-side pulley attached to a shaft extending from a crankshaft inthe engine to an outside, a. rotor-side pulley attached to the mainrotor, and a belt looped between the engine-side pulley and therotor-side pulley.

Also, in the engine-mounted autonomous flying device according to thepresent invention, when a direction in which a first engine part and asecond engine part constituting the engine are arrayed is a firstdirection, arid a direction which is perpendicular to the firstdirection is a second direction, the main rotor has a first main rotordriven by the first engine part and arranged on air outside along thefirst direction, and a second main rotor driven by the second enginepart and leveled at a position opposite the first main rotor, and thesub rotor has, on the first main rotor side, a first sub rotor arrangedon the outside along the second direction, and the second nib rotorarranged along the second direction at a. position opposite the firstsub rotor, and, on the second main rotor side, a third sub rotorarranged on the outside along the second direction, and the fourth subrotor arranged along the second direction at a position opposite thethird sub rotor.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the engine has a crankshaft with a first balance massformed thereon, and a balancer shaft with a second balance mass formedthereon at a symmetric position relative to the first balance mass; andthe main rotor is rotated by driving force from the crankshaft and thebalancer shaft.

Advantageous Effects of Invention

An engine-mounted autonomous flying device according to the presentinvention includes: a main rotor that gives main thrust to a fuselage; asub rotor that controls orientation of the fuselage; an engine thatgenerates energy for rotating the main rotor and the sub rotor; and anarithmetic control device that controls rotation of the sub rotor, andthe main rotor is rotated by being drivingly connected to the engine,the sub rotor is rotated by a motor driven by electric power generatedfrom a generator operated by the engine, and when orientation control totilt the fuselage is performed, the arithmetic control device increasesan output distribution ratio of the sub rotor to above an outputdistribution ratio of the sub rotor when hovering is performed. Thus, byincreasing the output distribution ratio of the sub rotor when theorientation control to tilt the fuselage is performed in order to causethe engine-mounted autonomous flying device to move in the air, thefuselage can be tilted in a preferable manner and moved.

Also, in engine-mounted autonomous flying device according to thepresent invention, the engine-mounted autonomous flying device accordingto claim 1, wherein the arithmetic control device sets the outputdistribution ratio of the sub rotor at 10% or more and 30% or less whenthe orientation control is performed. Thus, by setting the oiatii itdistribution ratio of the sub rotor at 10% or more when the orientationcontrol is performed, the sub rotor is provided with sufficientrotational force, so that the fuselage is tilted in the air in apreferable manner and moved. Also by setting the output distributionratio of the sub rotor at 30% or less, the orientation of the fuselagein the air can be stabilized.

Also, the engine-mounted autonomous flying device according to thepresent invention further includes: an electric power converter thatconverts the electric power generated from the generator; and acapacitor that stores electric power outputted from the electric powerconverter, and the arithmetic control device charges the capacitor whenthe hovering is performed, and supplies electric power discharged In thecapacitor to the motor when the orientation control is performed. Thus,by supplying electric power discharged by the capacitor to the motorwhen the orientation control is performed, it is possible to quicklyincrease the output of the sub rotor and cause the engine-mountedautonomous flying device to move at high speed in the air.

Also, in the engine-mounted autonomous flying device according to thepresent invention, a rotational speed of the engine when the hovering isperformed and a rotational speed of the engine when the orientationcontrol is performed are substantially same.. Thus, when the orientationcontrol is performed, the total energy required by the main rotor andthe sub rotor is larger than that when hovering is performed, but hi thepresent invention, the energy is replenished with electric energydischarged from the capacitor. This eliminates the need for increasingthe rotational speed of the engine for performing. the orientationcontrol. Hence, the orientation control can be simple.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the engine and the maim rotor are drivingly connectedvia a belt. Thus, by connecting the engine and the main rotor drivinglyvia a belt, they can be drivingly connected easily even when thedistance between the engine and the main rotor is long. Further, since abelt is lighter in weight than other mechanical power transmission meanssuch as gears, employing a belt makes it possible to reduce the weightof the engine-mounted autonomous flying device.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the engine has a first engine part having a firstpiston that reciprocates and a second engine part having a second pistonthat reciprocates while facing the first piston. Thus, since the pistonsarranged opposite each other in the first engine part and the secondengine part reciprocate, the vibrations and the like generated by thereciprocal motions cancel each other out. This can remarkably reduce thevibration generated by operation of the ergine.

Also, in the engine-mounted autonomous flying device according, to thepresent invention, the first piston and the second piston reciprocateinside a continuous cylinder. Thus, since the first piston and thesecond piston reciprocate inside the same cylinder, it is possible tosuppress the vibration generated from the engine and also simplify theconfiguration of the engine.

Also, in the engine-mounted autonomous flying, device according to thepresent invention, the first piston reciprocates inside a firstcylinder, and the second piston reciprocates inside a second cylinderformed as a separate body from the first cylinder. Thus, since the firstengine part and the second engine part individually have then cylinders,the first engine part and the second engine part can be preparedindividually. This can reduce the manufacturing cost. Further, theintake path and the exhaust path in each of the first cylinder and thesecond cylinder can be formed in shapes suitable for gas intake anddischarge.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the sub rotor is attached to a tip side of a sub annextending outward from a portion where the engine is arranged, and themain rotor is attached to a tip side of a main arm being longer than thesub arm and extending outward from the portion where the engine isarranged. Thus, by increasing the length of the main arm, to which themain rotor is attached, each rotor constituting the main rotor can belong. Accordingly, the payload can be increased further. Also, bydecreasing the length of the sub am, to which the sub rotor is attached,orientation control or the like via changing the rotational speed of thesub rotor can be performed in a precise manner.

Also, in the engine-mounted autonomous flying device according to thepresent invention, driving force is transmitted to the main rotor via anengine-side pulley attached to a shaft extending from a crankshaft inthe engine to an outside, a. rotor-side pulley attached to the mainrotor, and a belt looped between the engine-side pulley and therotor-side pulley. Thus, driving force generated from the engine can betransmitted to the main rotor with a relatively simple configuration.

Also, in the engine-mounted autonomous flying device according to thepresent invention, when a direction in which a first engine part and asecond engine part constituting the engine are arrayed is a firstdirection, and a direction which is perpendicular to the first directionis a second direction, the main rotor has a first main rotor driven bythe first engine part and arranged on an outside along the firstdirection, and a second main rotor driven by the second engine part andleveled at a position opposite the first main rotor, and the sub rotorhas, on the first main rotor side, a first sub rotor arranged on theoutside along the second direction, and the second sub rotor arrangedalong the second direction at a position opposite the first sub rotor,and, on the second main rotor side, a third sub rotor arranged on theoutside along the second direction, and the fourth sub rotor arrangedalong the second direction at a position opposite the third sub rotor.Thus, by having the first main rotor and the second main rotor atopposite end portions along the first direction and also having the foursub rotors, it is possible to increase the payload with the first mainrotor and the second main rotor and also to precisely control theorientation of the entire fuselage with the four sub rotors.

Also, in the engine-mounted autonomous flying device according to thepresent invention, the engine has a crankshaft with a first balance massformed thereon, and a balancer shaft, with a second balance mass formedthereon at a symmetric position relative to the first balance mass, andthe main rotor is rotated by driving force from the crankshaft and thebalancer shaft. Thus, it is possible to drive the rotors ithout having aplurality of engine parts by using mechanical power taken out from thecrankshaft and the balancer shaft.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a set of diagrams illustrating an autonomous flying device,according an embodiment of the present invention, FIG. 1A being aperspective view illustrating the autonomous flying device, and FIG. 1Bbeing a top view thereof.

FIG. 2 is a diagram illustrating the autonomous flying device accordingto the embodiment of the present invention, and is a block diagramillustrating a connection configuration of components.

FIG. 3 is a set of diagrams illustrating the autonomous flying deviceaccording to the embodiment of the present invention, FIG. 3A being aside cross-sectional view illustrating a. mounted engine, and FIG. 3Bbeing a. top cross-sectional view thereof.

FIG. 4 is a set of diagrams illustrating the autonomous flying deviceaccording to the embodiment of the present invention, FIG. 4A being, aside cross-sectional view illustrating another mounted engine, and FIG.4B being a top cross-sectional view thereof.

FIG. 5 is a diagram illustrating the autonomous flying device accordingto the embodiment of the present invention, and is a sidecross-sectional view illustrating still. another mounted engine.

FIG. 6 is a set of diagrams illustrating the autonomous flying deviceaccording to the embodiment of the present invention, FIG. 6Aillustrating a space-fixed coordinate system, and FIG. 6B illustrating afuselage-fixed coordinate system.

FIG. 7 is a set of diagrams illustrating the autonomous flying deviceaccording to the embodiment of the present invention, FIG. 7A being aside view illustrating the fuselage tilted at 10 degrees, and FIG. 7Bbeing a graph illustrating time-series changes in power.

FIG. 8 is a set of diagrams illustrating the autonomous device accordingto the embodiment of the present invention, FIG. 8A being a side viewillustrating the fuselage tilted at 35 degrees, and FIG. 8B being a gaphillustrating time-series changes in power.

DESCRIPTION OF EMBODIMENTS

A configuration of an engine-mounted autonomous flying device accordingto an embodiment will be described below with reference to the drawings.In the following description, parts having the same configuration willbe denoted by the same reference numeral, and description will not berepeated. Note that although up-down, front-rear, and left-rightdirections will be used in the following description, these directionsare for convenience of description. Also, in the following description,the ngine-mounted autonomous flying device will be referred to as anautonomous flying device 10. The engine-mounted autonomous flying deviceis also called a drone.

A schematic configuration of the autonomous flying device 10 accordingto the present embodiment will be described with reference to FIG. 1.FIG. 1A is a perspective view illustrating, the entirety of theautonomous flying, device 10, and FIG. 1B is a top view of theautonomous flying device 10.

Referring to FIG. 1A, the autonomous flying device 10 is a so-calledhybrid autonomous flying device. Specifically, a main rotor 14A and thelike are drivingly connected to an engine 30, while a sub rotor 15A andthe like are supplied with electric energy from the engine 30 via agenerator 16A and the like. In the following description, the main rotor14A and the like will also be referred to simply as main rotors 14, andthe sub rotor 15A and the like will also be referred to simply as subrotors 15. Here, the left-right direction in the sheet of FIG. 1 is afirst direction along which engine parts constituting the engine 30 arearrayed, and the front-rear direction in the sheet is a seconddirection.

The autonomous flying device 10 mainly has: a frame 11; the engine 30,which is disposed substantially at the center of the frame 11; thegenerator 16A and the like, which are driven by the engine 30; the subrotors 15, which are rotated by electric power generated by thegenerator 16A and the like; and the main rotors 14, which are rotated bybeing drivingly connected to the engine 30.

The frame 11 is formed in such a frame shape as to support the engine 30the generator 16A, various cables, and a control board (not illustratedhere), and so on. A metal or resin formed into the frame shape isemployed as the frame 11. On a lower end portion of the frame 11, skids18 are formed which contact the ground when the autonomous flying device10 lands on the ground. The frame 11 includes a main frame 12A and thelike that support the main rotors 14, and a sub flame 13A and the likethat support the sub rotors 15. The configurations of the main frame 12Aand the like and the sub frame 13A and the like will be described later.

The engine 30, the various cables, the control board (not illustratedhere), and so on are housed in a casing 17. The casing 17 is made of asynthetic resin plate material formed in a predetermined shape, forexample, and is fixed to a center portion of the frame 11. Here, thecasing 17 and the members incorporated therein will be referred to, as abody part 19.

The generators 16A and 16B are disposed above the engine 30. Thegenerators 16A and 16B generate electric power by being rotated by theengine 30. The electric power generated by the generators 16A and 16B issupplied to a motor 21 and the like that rotate the sub rotor 15A andthe like. That electric power is also supplied to an arithmetic controldevice that controls the rotation of the sub rotor 15A and the like, andso on.

The main frames 12A and 12B extend straight in the left-right directionfrom the body part 19. The main frames 12A and 12B are iriade of a metalor synthetic resin formed in a rod shape. The main rotor 14A isrotatably disposed at the left end of the main frame 12A, which extendsleftward. A pulley not illustrated is connected to the main rotor 14A,and a belt 20A is looped between the pulley on the main rotor 14A sideand a pulley not illustrated on the engine 30 side. The main rotor 14B,on the other hand, is rotatably disposed at the right end of the mainframe 12B, which extends rightward. A pulley not illustrated isconnected to the main rotor 14B, and a belt 20B is looped between thepulley on the main rotor 14B side and a pulley not illustrated on theengine 30 side. With this configuration, the main rotors 14 aredrivingly connected to the engine 30. Thus, the main rotors 14 arerotated directly by the mechanical power generated by the engine 30, andtherefore the energy loss that occurs when energy is transmitted fromthe engine 30 to the main rotors 14 is smaller than that of a seriestype.

The main rotors 14 have a function of generating lift that causes theautonomous flying device 10 to float in the air. The sub rotors 15, onthe other hand, mainly serve to control the orientation of theautonomous flying device 10. For example. the sub rotors 15 rotate asappropriate so as to maintain the position and orientation of theautonomous flying device 10 when the autonomous flying device 10 ishovering. The sub rotors 15 also rotate so as to tilt the autonomousflying, device 10 when the autonomous flying device 10 moves. Meanwhile,the main rotor 14A and a main rotor 14B rotate in opposite directions.

The sub frame 13A and the like extend in the front-rear direction and,like the above main frame 12A and the like, are made of a metal orsynthetic resin formed in a rod shape. The sub frame 13A and the likeextend from intermediate portions of the main frame 12A and the like.The sub rotor 15A is disposed at the front end of the sub frame 13A, andthe sub rotor 15A is rotated by the motor 21A, which is disposed underit. A sub rotor 15B is disposed at the front end of a sub frame 13B, andthe sub rotor 15B is rotated by a motor 21B disposed under it. A subrotor 15C is disposed at the rear end of a sub frame 13C, and the subrotor 15C is rotated by a motor 21C disposed under it. A sub rotor 15Dis disposed at the rear end of a sub frame 13D, and the sub rotor 15D isrotated by a motor 21D disposed under it. The motors 21A, 21B, 21C, and21D are supplied with electric power generated by the generators 16A and16B. Inside the sub frame 13A and the like are routed cables forsupplying electric power to the motor 21A.

Referring to FIG. 1B, a length L10 of the main frame 12A (the lengthfrom the center of the body part 19 to the left end of the main frame12A) is longer than each single blade on the main rotor 14A. Thisprevents the rotating main rotor 14A from contacting the body part 19.Further, the length L10 of the main frame 12A is set to be sufficientlylong so that the main rotor 14A will not contact the sub rotors 15A and15C. The length of the main frame 12B is equal to that of the main frame12A.

A length L20 of the sub frame 13D is longer than the length of eachsingle blade on the sub rotor 15D so that the sub rotor 15D will notcontact the body part 19. Also, the length L20 of the sub frame 13D (thelength from the center of the body part 19 to the rear end of the subframe 13D) is such a length as to avoid contact with the main rotor 14B.Here, the lengths of the other sub rotors 15A, 15B, and 15C are equal tothat of the sub rotor 15D. Also, the lengths of the other sub frame 13Aand the like are equal to that of the sub frame 13D. Further. the lengthL10 of the main frame 12A is sufficiently longer than the length L20 ofthe sub frame 13D.

The above main rotors 14 and sub rotors 15 are arranged to beline-system with respect to a left-right direction symmetry line passingthe center of the body part 19 along the left-right direction. The abovemain rotors 14 and sub rotors 15 are also arranged to be line-symmetricwith respect to a front-rear direction symmetry line passing the centerof the body part 19 along the front-rear direction. This symmetricarrangement of the main rotors 14 and the sub rotors 15 can stable theposition and orientation of the autonomous flying device 10 while theautonomous flying device 10 is in the air.

The main rotor 14 and the like and the sub rotor 15A and the like rotatesimultaneously when the autonomous flying device 10 with the aboveconfiguration flies. Thrust generated by rotation of the main rotor 14and the like makes the ous flying device 10 float, and the sub rotor15,A and the like rotate individually to control the position andorientation of the autonomous flying device 10 in the air. To move theautonomous flying device 10, orientation control to tilt the autonomousflying device 10 is executed by changing the rotational speeds of thesub rotor 15A and the like while rotating the main rotor 14 and the likeat a predetermined speed. This orientation control will be describedlater.

A connection configuration in the autonomous flying device 10 will bedescribed with reference to a block diagram in FIG. 2. The autonomousflying device 10 has an arithmetic control device 31 that controls itsposition and orientation in the air. The arithmetic control device 31includes a CPU, a RAM, a ROM, and so on, and controls the rotation ofthe motor 21A and the like, which drive the sub rotor 15A and the like,based on instructions from various sensors, a camera, and an operatingdevice that are not illustrated here. The operating device here is aso-called controller that is wirelessly connected or wired to theautonomous flying device 10 and enables a user to manipulate theposition, altitude, moving direction, moving speed, and the like of theautonomous flying device 10.

As described above, the autonomous flying device 10 is capable offloating in the air and moving in a predetermined direction by rotatingthe main rotors 14 and the sub rotors 15 with driving energy generatedby the engine 30, as described above. Also, the autonomous flying device10 controls its position and orientation in the air by controlling therotational speeds of the motor 21A and the like, which rotate the subrotors 15.

The engine 30 is the energy source for the tor 21A and the like. Thegenerator 16A and the like, an inverter 32 (electric power converter), acapacitor module 34, and a driver 24A and the like are interposedbetween the engine 30 and the motor 21A and the like. With thisconfiguration, driving, force generated from the engine 30 is convertedinto electric power, and the motor 21A and the like are rotated atpredetermined rotational speeds with this electric power to therebycontrol the position and orientation of the autonomous flying device 10and move the autonomous flying device 10.

As will be described later, the engine 30 is of a reciprocating typethat uses gasoline or the like as the fuel, and drives the generators16A and 16B with its driving force. Here, as described above, the engine30 drives the main rotors 14 as well. The engine 30 is controlled by thearithmetic control device 31.

AC electric power generated from the generators 16A and 16B is suppliedto the inverter 32. In the inverter 32, firstly a converter circuitconverts the AC electric power into DC electric power, and then aninverter circuit converts the DC electric power into AC electric powerof a predetermined frequency. During hovering, part of the electricpower outputted from the inverter 32 is stored in the capacitor module34. The electric power stored in the capacitor module 34 is supplied tothe motor 21A and the like when the autonomous flying device 10 changesits position andlor orientation. The capacitor module 34 is capable ofsupplying a large current to the load in a short time as compared to arechargeable battery or the like. This makes it possible toinstantaneously increase the rotational speeds of the motor 21A and thelike and thus quickl move the autonomous flying device 10.

Also, part of the electric power outputted from the inverter 32 issupplied to an excess electric power consumption circuit 33 as well. Theexcess electric power consumption circuit 33 is a circuit that consumespart of the electric power converted by the inverter 32 which is not tobe used by the motor 21A or the like. Including the excess electricpower consumption circuit 33 enables stable operation of the engine 30and the inverter 32. The behavior of the inverter 32 is controlled bythe arithmetic control device 31.

Using the electric power generated from the inverter 32, the drivers24A, 24B, 24C, and 24D respectively control the amounts of current to beflowed into the motors 21A, 21B, 21C, and 21D, their rotationdirections, their rotation timings, and so on. The behaviors of thedrivers 24A, 24B, 24C, and 24D are controlled by the arithmetic controldevice 31.

The autonomous flying device 10 with the above configuration usesdifferent electric power supply system for a hovering state in which theautonomous flying device 10 stays at one spot in the air and a movingstate in which the autonomous flying device 10 moves toward a certainlocation.

Specifically, in the hovering state, electric power is supplied from thegenerators 16A and 16B to the inverter 32, the driver 24A and the like,the motor 21A and the like in this order. Then. the arithmetic controldevice 31 rotates the motor 21A at predetermined rotational speeds bycontrolling the driver 24A and the like based on the outputs from thevarious sensors such that the autonomous flying device 10 stays at onespot while maintaining a. horizontal position relative to the ground. Inthis way, the sub rotor 15A and the like illustrated in FIG. 1 rotate atpredetermined speeds. Hence, the autonomous flying device 10 hoversstably.

On the other hand, in the moving state where the autonomous flyingdevice 10 is caused to move, the arithmetic control device 31 firstlysupplies the electric power stored in the capacitor module 34 to thedriver 24A and the like based on the user's instruction from thecontroller or the like. Thus, the driver 24 and the like are suppliedwith electric power from the capacitor module 34 in addition to theelectric power supplied from the inverter 32. For example, referring toFIG. 1, to cause the autonomous flying device 10 to move forward, thearithmetic: control device 31 controls the driver 24A and the like so asto supply the supplied electric power to the motors 21C and 2113, whichdrive the sub rotors 15C and 15D, and thereby make the rotational speedsof the sub rotors 15C and 15D higher than the rotational speeds of thesub rotors 15A and 15B.

As a result, the autonomous flying device 10 tilts to slightly turncounterclockwise in a view of the autonomous flying device 10 from theright. The main rotors 14A and 14B are rotated in this tilted state.Thus, a combined force of the lift generated by the main rotors 14A and14B and the gravity exerted on the autonomous flying device 10 isexerted forward. Consequently, the autonomous flying device 10 movesforward.

After the autonomous flying device 10 moves to a predetermined spot, thearithmetic control device 31 stops the supply of electric power from thecapacitor module 34 to the driver 24A and the like to thereby rotate themotor 21A and the like at a substantially equal speed via the driver 24Aand the like. Thus, the autonomous flying device 10 hovers again.

As described above, the autonomous flying device 10 according to thepresent embodiment is a so-called hybrid type having the main rotor 14and the like, which are rotated by driving force from the engine 30, andthe sub rotor 15A and the like, which are rotated by the motor 21 andthe like, which are driven by the engine 30. Thus, compared to theabove-mentioned series type, the autonomous flying device 10 can improvethe energy consumption by approximately 50%.

Next, configurations of the engine 30 mounted on the autonomous flyingdevice 10 with the above configuration will be described with referenceto FIGS. 3 to 5. The autonomous flying device 10 according to thepresent embodiment employs a vibration-free or low-vibration engine asthe engine 30 since the position and orientation of the autonomousflying device 10 in the air cannot be precisely controlled if the engine30 generates a large vibration.

One form of the engine 30 will be described with reference to FIG. 3.FIG. 3A is a cross-sectional view of the engine 30 as viewed from thefront, and FIG. 3B a cross-sectional view of the engine 30 as viewedfrom above. The engine 30 illustrated here has two engine parts (firstengine part 40 and secondengine part 41) arranged opposite each other inthe left-right dirction.

Referring to FIGS. 3A and 3B, the engine 30 has the first engine part 40and the second engine part 41, which are arranged on the left side andthe right side in the sheet of the figures, respectively.

The first engine part 40 has: a first piston 43 that reciprocates in theleft-right direction; a first crankshaft 42 that converts the reciprocalmotion of the first piston 43 into rotational motion; and a firstconnecting rod 44 that rotatably couples the first piston 43 and thefirst crankshaft 42.

The second engine part 41 has: a second piston 46 that reciprocates inthe left-right direction; a second crankshaft 45 that converts thereciprocal motion of the second piston 46 into rotational motion; and asecond connecting rod 47 that rotatably couples the second piston 46 andthe second crankshaft 45.

A pulley 22 and the generator 16A are connected to the upper end side ofthe first crankshaft 42. Also, a pulley 23 and the generator 16B areconnected to the upper end side of the second crankshaft 45.

The first piston 43 of the first engine part 40 and the second piston 46of the second engine part 41 share a combustion chamber 48. In otherwords, the first piston 43 and the second piston 46 reciprocate inside asingle continuous cylinder. In this way, the first engine part 40 andthe first piston 43 move back and forth simultaneously toward thecenter, and thus the ratio of expansion of a mixed gas in the combustionchamber 48 can be high while the amount of stroke is reduced.

Also, in the engine 30, a volumetric space not illustrated here isformed which communicates with the combustion chamber 48, and a sparkplug is arranged in this volumetric space. Also, an intake port and anexhaust port not illustrated here are formed in the combustion chamber48. A mixed gas containing a fuel such as gasoline is introduced throughthe intake port into the combustion chamber 48, and the exhaust gasafter combustion is discharged from the combustion chamber to theoutside through the exhaust port.

Referring to FIG. 3A, the engine 30 with the above configurationoperates as below. First is an intake stroke in which the first piston43 and the second piston 46 move outward inside a cylinder 49 from itscenter, thereby introducing a nixed gas being a. mixture of the fuel andair into the cylinder 49. Next is a compression stroke in which thefirst piston 43 and the second piston 46 are pushed toward the center bythe inertia, of the rotating first crankshaft 42 and second crankshaft45. thereby compressing the mixed gas inside the cylinder 49. Next is acombustion stroke in which the spark plug not illustrated sparks insidethe combustion chamber 48, thereby combusting the mixed gas inside thecylinder 49 and thus pushing the first piston 43 and the second piston46 to the outer ends, which are the respective bottom dead centers.After this is an exhaust stroke in which the first piston 43 and thesecond piston 46 are pushed inward by the inertia of the rotating firstcrankshaft 42 and second crankshaft 45, thereby discharging the gasafter the combustion present in the cylinder 49 to the outside.

In the present form of the engine 30, the two first and second pistons43 and 46, which reciprocate inside the single cylinder 49, split eachstroke. Thus, the ratio of compression of the mixed gas can be higherthan that of a normal gasoline engine. Also, since the first piston 43and the second piston 46 face each other in the cylinder 49, a cylinderhead, which is required for a typical engine, is not required. Thus, theconfiguration of the engine 30 is simple and light in weight. Also, themembers constituting the engine 30, i.e. the first piston 43 and thesecond piston 46, the first crankshaft 42 and the second crankshaft 45,and so on are arranged opposite each other and operate opposite eachother. Thus, the vibrations generated by the sets of members of theengine 30 cancel each other out. This can reduce the vibration generatedon the outer side from the entire engine 30. Hence, with the presentform, it is possible to reduce the size, weight, and vibration of theautonomous flying device 10 by mounting the engine 30 with the abovestructure. In particular, with the vibration reduced, it is possible toprevent adverse effects on precision equipment such as the arithmeticcontrol device for the orientation control, the motor output control,and so on, and a GPS sensor. It is also possible to prevent theautonomous flying device 10 from damaging a delivery package theautonomous flying device 10 is transporting with its vibration.

Another form of the ermine 30 will be described with reference to FIG.4. FIG. 4A is a side view of the engine 30 as viewed from the front, andFIG. 4B is a top view of the engine 30.

Referring to FIGS. 4A and 4B. the engine 30 in the present case includesa first engine part 60 on the left and a second engine part 61 on theright, and an individual cylinder is formed in each of the engine parts.This feature differs from the engine 30 illustrated in FIG. 3.

The first engine part 60 has: a first cylinder 71; a first piston 70that reciprocates inside the first cylinder 71 a first crankshaft 80that converts the reciprocal motion of the first piston 70 intorotational motion; a first connecting rod 75 that rotatably couples thefirst piston 70 and the first crankshaft 80; a first intake valve 64;and a first exhaust valve 62.

The second engine part 61 has: a second cylinder 73; a second piston 72that reciprocates inside the second cylinder 73; a second crankshaft 81that converts the reciprocal motion of the second piston 72 intorotational motion; a second connecting rod 76 that rotatably couples thesecond piston 72 and the second crankshaft 81; a second intake valve 65;and a second exhaust valve 63.

Here, the above first engine part 60 and second engine part 61 maybehoused in an engine block formed as a single body by casting, or thefirst engine part 60 and the second engine part 61 may be housed inseparate engine blocks.

In the engine 30, the main constituent components constituting the firstengine part 60 and the second engine part 61 are arranged along theleft-right direction. Specifically, the first cylinder 71, the firstpiston 70, the first crankshaft 80, and the first connecting rod 75 ofthe first engine part 60 are arranged along the left-right direction.Further, the second cylinder 73, the second piston 72, the secondcrankshaft 81, and the second connect ng rod 76 of the second enginepart 61 are also arranged along the left-right direction. By arrangingthe constituent components of each engine part along the left-rightdirection as described above, the vibrations generated by operation ofthe engine parts cancel each other out. This can improve the vibrationsuppression effect.

Further, the first engine part 60 and the second engine part 61 arearranged symmetrically in the left-right direction. With thisconfiguration too, the vibrations generated by operation of the engineparts cancel each other out. This can improve the vibration suppressioneffect.

Referring to FIGS. 4A and 4B, the first engine part 60 has a valve drivemechanism that controls the operation of the above-mentioned firstintake valve 64 and second intake valve 65.

This valve drive mechanism has a crank pulley 82, a cam pulley 85, and atiming belt 74 looped between the crank pulley 82 and the cam pulley 85.The crank pulley 82 is connected to a portion of the first crankshaft 80extending to the outside. The cam pulley 85 is connected to a cam shaft86 along with a first intake cam 84 that contacts the first intake valve64 to control its forward-backward motion and a second intake cam 87that contacts the second intake valve 65 to control its forward-backwardmotion. The first intake cam 84 and the second intake cam 87 areconnected to the cam shaft 86 with such a phase difference as tosynchronize the timing with which the first intake cam 84 presses thefirst intake valve 64 and the timing with which the second intake cam 87presses the second intake valve 65 with each other.

Referring to FIG. 4A, the pulley 22 and the generator I 6A are connectedto the upper end side of the first crankshaft 80 of the first enginepart 60. and the pulley 23 and the generator 16B are connected to theupper end side of the second crankshaft 81 of the second engine part 61.

There is a mechanism that drives the first exhaust valve 62 and thesecond exhaust valve 63, the mechanism having a crank pulley 83, a campulley 67, and a timing belt 77 looped between the crank pulley 82 andthe cam pulley 85. The crank pulley 83 is connected to a portion of thesecond crankshaft 81 extending to the outside. The cam pulley 67 isconnected to a cam shaft 66 along nvith a first exhaust cam 78 thatcontacts the first exhaust valve 62 to control its forward-backwardmotion and a second exhaust cam 79 that contacts the second exhaustvalve 63 to control its forward-backward motion. The first exhaust cam78 and the second exhaust cam 79 are connected to the cam shaft 66 withsuch a. phase difference as to synchronize the timing with which thefirst exhaust cam 78 presses the first exhaust valve 62 and the timingwith Which the second exhaust cam 79 presses the second exhaust valve 63with each other.

As illustrated in FIG. 4A, a reversing gear 68 is connected to the camshaft 66, to which the first exhaust cam 78 and the like are attached.Also, a reversing gear not illustrated here is connected to the camshaft 86 (FIG. 4B) as well. Further, the reversing gear 68 on the camshaft 66 and the reversing gear on the cam shaft 86 are meshed with eachother. With this configuration, a crankshaft reversal-synchronizationmecha ism is formed which causes the first crankshaft 80 and the secondcrankshaft 81 to rotate in opposite directions.

The operation of the engine 30 illustrated in FIG. 4 is basicallysimilar to that illustrated in FIG. 3. Specifically, the first piston 70and the second piston 72 perform a. compression stroke and the like bysimultaneously- moving inward in the left-right direction, and executesa combustion stroke and the like by simultaneously moving outward in theleft-right direction. Also, with the above configuration, a flow path 88and a flow path 89 being intake-exhaust paths are simple, therebyenabling efficient gas intake and discharge.

Another form of the engine 30 employed in the autonomous flying device10 according to the present embodiment will be described with referenceto FIG. 5. The engine 30 to be discussed here has a single piston 104,and takes out driving force from a crankshaft 100 and a balancer shaft107.

Specifically, the engine 30 has: a cylinder 105; the piston 104, whichreciprocates inside the cylinder 105; the crankshaft 100, which convertsthe reciprocal motion of the piston 104 into rotational motion; aconnecting rod 103 which rotatably couples the piston 104 and thecrankshaft 100. A crank gear 102, the pulley 22, and the generator 16Aare attached to the upper end side of the crankshaft 100. Balance masses101 are also attached to the crankshaft 100. Attaching the balancemasses 101 can reduce primary inertia force generated by rotation of thecrankshaft 100.

The balancer shall 107 is disposed to the right of the crankshaft 100.The balancer shaft 107 is a so-called eccentric shaft. The balancershaft 107 is capable of reducing the vibration generated by rotation ofthe crankshaft 100 by rotating along with the crankshaft 100. A balancergear 109, a flywheel 110, the pulley 23, and the generator 16B areattached to the upper end side of the balancer shaft 107.

Balance masses 106 are attached to the balancer shaft 107. The balancemasses 101 fimmed on the crankshaft 100 and the balance masses 106formed on the balancer shaft 107 have a symmetrical positionalrelationship. Specifically, the positional relationship between thebalance masses 101 and the balance masses 106 is such that they areline-symmetric with respect to a symmetry line 111 extending verticallyat the midpoint between the rotational center of the crankshaft 100 andthe rotational center of the balancer shaft 107.

The balance masses 106 may be formed only on the balancer shaft 107, butthe balance masses 106 are formed on the balancer shaft 107 and thebalancer gear 109 in the present case. Also, the moment of inertia aboutthe balancer shaft 107 including the balance masses 106 and the momentof inertia about the crankshaft 100 including the balance masses 101 areequal or substantially equal. This can further reduce the vibrationgenerated by operation of the engine 30.

Here, the flywheel 110 can be formed on the balancer shaft 107. In thiscase, the moment of inertia about the balancer shaft 107 including theflywheel 110 and the moment of inertia about the crankshaft 100 is setto be equal. This can further increase the vibration suppression effect.

Output distribution ratios for tilting the autonomous flying device 10for movement will be described with reference to FIGS. 6 to 8. FIG. 6 isa set of diagrams for explaining a coordinate system used forsimulation. FIG. 7A is a side view illustrating the autonomous flyingdeuce 10 tilted at 10 degees, and FIG. 7B is a graph illustratingtime-series changes in output power in this case. FIG. 8A is a side viewillustrating the autonomous flying device 10 tilted at 35 degrees, andFIG. 8B is a graph illustrating time-series changes in output power inthis case.

First, equations of motion used to simulate the output of the autonomousflying device 10 will be described with reference to FIG. 6. FIG. 6A isa graph illustrating a space-fixed coordinate system, and FIG. 6B is agraph illustrating a fuselage-fixed coordinate system.

When a space-fixed coordinate system is defined as FIG. 6A and afuselage-fixed coordinate system is defined as FIG. 6B, the relationshipbetween these two fixed coordinate systems can be described asmathematical equation 1 below. Here, ϕ, θ, and ψ are Euler anglesrepresenting roll, pitch, and spin, respectively.

$\begin{matrix}{{\begin{Bmatrix}x \\y \\z\end{Bmatrix} = {R \cdot \begin{Bmatrix}X \\Y \\Z\end{Bmatrix}}},{R = \begin{bmatrix}{\cos \; \psi \; \cos \; \theta} & {\sin \; \psi \; \cos \; \theta} & {{- \sin}\; \theta} \\{{\cos \; \psi \; \sin \; \theta \; \sin \; \varphi} - {\sin \; \psi \; \cos \; \varphi}} & {{\sin \; \psi \; \sin \; \theta \; \sin \; \varphi} - {\cos \; \psi \; \cos \; \varphi}} & {\cos \; \theta \; \sin \; \varphi} \\{{\cos \; \psi \; \sin \; \theta \; \cos \; \varphi} + {\sin \; \psi \; \sin \; \varphi}} & {{\sin \; \psi \; \sin \; \theta \; \cos \; \varphi} - {\cos \; \psi \; \sin \; \varphi}} & {\cos \; \theta \; \cos \; \varphi}\end{bmatrix}}} & \left\lbrack {{Math}.\mspace{14mu} 1} \right\rbrack\end{matrix}$

Also, translational motion of a center of gravity {X_(G), Y_(G),Z_(G)}^(T) of the autonomous flying device 10 is described asmathematical equation 2 below in the space-fixed coordinate system.Here, m denotes the weight of the fuselage of the autonomous flyingdevice 10, g denotes the gravitational acceleration, and T denotes thethrust generated by the main rotor 14A and the like and the sub rotor15A and the like.

$\begin{matrix}{{m\begin{Bmatrix}\overset{¨}{X_{G}} \\\overset{¨}{Y_{G}} \\\overset{¨}{Z_{G}}\end{Bmatrix}} = {{{m\begin{Bmatrix}0 \\0 \\{- g}\end{Bmatrix}} + T} = \begin{Bmatrix}{{\cos \; \psi \; \sin \; \theta \; \cos \; \varphi} + {\sin \; \psi \; \sin \; \varphi}} \\{{\sin \; \psi \; \sin \; \theta \; \cos \; \varphi} - {\cos \; \psi \; \sin \; \varphi}} \\{\cos \; \theta \; \cos \; \varphi}\end{Bmatrix}}} & \left\lbrack {{Math}.\mspace{14mu} 2} \right\rbrack\end{matrix}$

Further, rotational motion of the autonomous flying device 10 about itscenter of gravity is described as mathematical equation 3 below in thefuselage-fixed coordinate system. Here, I_(XX), I_(YY), and I_(ZZ)denote the moments of inertia of the fuselage shout the axes, {W₁, W₂,W₃}^(T) denotes the angular velocity vectors, and {τ_(ϕ), τ_(θ),τ_(ψ)}^(T) denotes the torques about the axes generated by theorientation control rotors.

$\begin{matrix}{{\begin{Bmatrix}{I_{xx}\overset{.}{W_{1}}} \\{I_{yy}\overset{.}{W_{2}}} \\{I_{zz}\overset{.}{W_{3}}}\end{Bmatrix} - \begin{Bmatrix}{\left( {I_{yy} - I_{zz}} \right)W_{2}W_{3}} \\{\left( {I_{zz} - I_{xx}} \right)W_{3}W_{1}} \\{\left( {I_{xx} - I_{{yy}\;}} \right)W_{1}W_{2}}\end{Bmatrix}} = \begin{Bmatrix}\tau_{\varphi} \\\tau_{\theta} \\\tau_{\psi}\end{Bmatrix}} & \left\lbrack {{Math}.\mspace{14mu} 3} \right\rbrack\end{matrix}$

Motion of the autonomous flying device 10 was simulated based on theabove equations, and the following result,was obtained.

In this simulation, observed was the difference in power distributionratio between during hovering and during orientation control. Here,during orientation control refers to when the autonomous flying device10 was tilted at, e.g., 10 degrees in order to cause the autonomousflying device 10 to move in the air. Also, the power distribution ratiorefers to the ratio of the power generated by rotation of the main rotor14A and the like and the power generated by rotation of the sub rotor15A and the like.

While the autonomous flying device 10 is hovering, the main rotor 14Aand the like generate a thrust that causes the device body to floatwhereas the sub rotor 15A and the like rotate to make the device bodystay at ar certain spot and maintain a parallel state. Thus, the outputof the main rotor 14 and the like is far larger than the output of thesub rotor 15A and the like. For example, the power outputted by the mainrotor 14 and the like is 3.04 W whereas the power outputted by the subrotor 15A and the like is 0.34 W. In an example, the output distributionratio of the main rotor 14 and the like and the sub rotor 15A and thelike is 90%:10%.

Since the main rotor 14 and the like and the output shafts of the engine30 are drivingly connected, the energy loss over the energy transmissionpath from the engine 30 to the main rotor 14 and the like is remarkablysmall. In other words, the energy efficiency over the energytransmission path from the engine 30 to the main rotor 14 and the likeis remarkably high. On the other hand, since the sub rotor 15A and thelike are supplied with energy from the engine 30 via the generator 16Aand the like, the inverter 32, the motor 21A and the like, asillustrated in FIG. 2 and other figures, the energy efficiency overthese paths is, for example, 70%, which is low, Thus, during hovering,the output distribution ratio of the main rotor 14 and the like is setlarge. In this way, the energy generated by the engine 30 can beefficiently used to float the autonomous flying device 10.

During orientation control, on the other hand, the sub rotor 15A and thelike are rotated at high speed in order to tilt the autonomous flyingdevice 10. Accordingly, the ratio of energy supplied to the sub rotor15A and the like is larger than that during hovering. Also, the largerthe angle of tilt of the autonomous flying device 10, the faster the subrotor 15A. and the like need to be rotated, and thus the larger theratio of energy to be supplied to the sub rotor 15A and the like.

A case where the autonomous flying device 10 is tilted at 10 degrees inorientation control will be described with reference to FIG. 7. FIG. 7Ais a side view illustrating a state where the autonomous flying device10 is tilted at 10 degrees, and FIG. 7B is a graph illustratingtime-series changes in the powers generated by the rotors. Here, thepowers refer to the thrusts Which the rotors generate by rotating.

Referring to FIG. 7A, in orientation control, the arithmetic controldevice 31 rotates the sub rotors 15C and 15D at a. higher speed than thesub rotors 15A and 15B, so that the lift exerted on the rear of theautonomous flying device 10 is larger than the lift exerted, on thefront thereof. As a result, the autonomous flying device 10 is tiltedcounterclockwise. Here, the sub rotor 15A and the like are rotated suchthat the tilt angle θ of the autonomous flying device 10 can be 10degrees.

In the graph illustrating in FIG. 7B, the horizontal axis representstime while the vertical axis represents the powers generated by therotors. Here, the long-dashed short-dashed line indicates the power ofthe sub rotor 15A and the like, the dotted line indicates the power ofthe main rotor 14 and the like, and the solid line represents the totalof the power of the sub rotor 15A and the like and the power of the mainrotor 14 and the like.

Referring to this diagram, at a time T1, the sub rotors 15C and 15D arerotated at higher speed than the sub rotors 15A and 15B, so that thepower of the sub rotor 15A and the like indicates the largest value(approximately 0.5 kW). As a result, the tilt angle of the autonomousflying device 10 becomes 10 degrees, as described above. In this state,the rotational speed of the sub rotors 15C and 15D is set to beequivalent to that of the sub rotors 15A and 15B, so that the autonomousflying device 10 moves forward with the thrust from the main rotor 14and the like. Meanwhile, in the present embodiment, the rotational speedof the sub rotors 15C and 15D can be instantaneously increased withelectric power supplied from the capacitor module 34 illustrated in FIG.2.

Then, at a time T2, the autonomous flying device 10 reaches apredetermined speed and thus the rotational speed of the sub rotors 15Aand 15B is increased to above that of the sub rotors 15C and 15D so thatthe autonomous flying device 10 can be in a parallel state. At this timetoo, the power of the sub rotor 15A and the like becomes relatively highbut is lower than the power in the time T1.

From the time T1 to the time T2 the autonomous flying device 10 istilted to accelerate, and at the time T2 the autonomous flying device 10is put into the parallel state, thereby reducing to the acceleration tozero. After the time T2 the autonomous flying device 10 moves at aconstant speed.

During the orientation control of the autonomous flying device 10, theoutput of the main rotor 14 and the like remains basically uncharged andis approximately 3 kw. Meanwhile, during this state, the rotationalspeed of the engine 30 may be constant or set at a high speed ifnecessary.

When the autonomous flying device 10 is tilted at 10 degrees asdescribed above, the largest power of the sub rotor 15A and the like isapproximately 0.6 kw and the power of the main rotor 14 and the like isapproximately 3.0 kw. Thus, the output distribution ratio of the mainrotor 14 and the like and the sub rotor 15A and the like is 86%:14%.

A case where the autonomous flying device 10 is tilted at 35 degreeswill be described with reference to FIG. 8. FIG. 8A is a side viewillustrating the autonomous flying device 10 tilted at 35 degrees, andFIG. 8B is a graph illustrating time-series changes in power Here, thecontrol method of tilting the autonomous flying device 10 to move it issimilar to that illustrated in FIG. 7. By setting the tilt angle 6 ofthe autonomous flying device 10 at such a large angle, the autonomousflying device 10 can be caused to move at higher speed.

Retelling to FIG. 8B, tilting the autonomous flying device 10 at 35degrees requires the sub rotors 15C. and 15D to rotate at a furtherhigher speed, Thus, the largest value of the sub rotor 15A and the likeat a time T3 is approximately 1,3 kw. Also, at a time T4, the power ofthe sub rotor 15A and the like becomes large again in order to put theautonomous flying device 10 into a parallel state. Here, from the timeT3 to the time T4 the autonomous flying device 10 is tilted toaccelerate, and at the time T4 the autonomous flying device 10 is putinto the parallel state, thereby reducing to the acceleration to zero.After the time T4 the autonomous flying device 10 moves at a constantspeed. In this case, since the autonomous flying device 10 is steeplytilted the acceleration exerted on the autonomous flying device 10 islarge. Accordingly, the autonomous flying device 10 can he moved at highspeed.

As described above, during the orientation control of the autonomousflying device 10, the output of the main rotor 14 and the like remainsbasically unchanged and is approximately 3 kw Meanwhile, during thisstate, the rotational speed of the engine 30 may be constant.

Thus, when the autonomous flying device 10 is tilted at 35 degrees tomove, the output distribution ratio of the main rotor 14 and the likeand the sub rotor 15A and the like is 70%:30%, for example. That is, theoutput of the sub rotor 15A and the like is larger than that when theautonomous flying device 10 is tilted at 10 degrees.

In the present embodiment. When the orientation of the autonomous flyingdevice 10 is changed. the output distribution ratio of the sub rotor 15Aand the like is increased to above that during hovering. Thus, the subrotor 15A and the like are rotated at high speed with the autonomousflying device 10 caused to float using thrust from the main rotor 14 andthe like. This enables the autonomous flying device 10 toinstantaneously tilt and move.

Meanwhile, in the changing of the orientation of the autonomous flyingdevice 10, the output distribution ratio of the sub rotor 15A and thelike when the output of the sub rotor 15A and the like is largest ispreferably 10% or more and 30% or less. By setting this outputdistribution ratio at 10% or more, the sub rotors are provided withsufficient rotational force, so that the autonomous flying device 10 canbe tilted in the air in a preferable Manner and moved. Also, by settingthe distribution ratio at 30% or less, the orientation of the autonomousflying device 10 in the air can he stabilized.

Generally, changing the orientation of a multi-rotor autonomous flyingdevice requires an output response on the order of 100 msec. Since theoutput response speed of engine-driven autonomous flying devices is riotsufficiently high, it is not easy to accurately control theirorientations. On the other hand, the autonomous flying device 10according to the present embodiment electronically controls therotational speed of the motor 21A and the like, which rotate the subrotor 15A and the like, to control the orientation of the autonomousflying device 10. This enables an output response on the order of 100msec. Thus, the orientation of the autonomous flying device 10 can becontrolled accurately.

While an embodiment of the present invention has been described above,the present invention is not limited to the above embodiment.

Referring to FIG. 2, the autonomous flying device 10 may be equippedwith a rechargeable battery Specifically, part of the electric powergenerated by the generator 16A and the like may be stored in arrechargeable battery, and electric power discharged from therechargeable battery may be used as appropriate to rotate the motor 21Aand the like.

Referring to FIG. 1, the driving force from the engine 30 is transmittedto the main rotor 14 and the lake via the belt 20A and the like, but thedriving force from the engine 30 may be transmitted to the main rotor 14and the like via other mechanical power transmission means such as agear train.

REFERENCE SIGNS LIST

-   10 autonomous flying device-   11 frame-   12, 12A, 12B main frame-   13, 13A, 13B, 13C, 13D sub frame-   14, 14A, 14B main rotor-   15, 15A, 15B, 15C, 15D sub rotor-   16, 16A, 16B generator-   17 casing-   18 skid-   19 body part-   20, 20A, 20B belt-   21, 21A, 21B, 21C, 21D motor-   22 pulley-   23 pulley-   24, 24A, 24B, 24C, 24D driver-   30 engine-   31 arithmetic control device-   32 inverter-   33 excess electric power consumption circuit-   34 capacitor module-   40 first engine part-   41 second engine part-   42 first crankshaft-   43 first piston-   44 first connecting rod-   45 second crankshaft-   46 second piston-   47 second connecting rod-   48 combustion chamber-   49 cylinder-   60 first engine part-   61 second engine part-   62 first exhaust valve-   63 second exhaust valve-   64 first intake valve-   65 second intake valve-   66 cam shaft-   67 cam pulley-   68 reversing gear-   70 first piston-   71 first cylinder-   72 second piston-   73 second cylinder-   74 timing belt-   75 first connecting rod-   76 second connecting rod-   77 timing belt-   78 first exhaust cam-   79 second exhaust cam-   80 first crankshaft-   81 second crankshaft-   82 crank pulley-   83 crank pulley-   84 first intake cam-   85 cam pulley-   86 cam shaft-   87 second intake cam-   88 flow path-   89 flow path-   100 crankshaft-   101 balance mass-   102 crank gear-   103 connecting rod-   104 piston-   105 cylinder-   106 balance mass-   107 balancer shaft-   109 balancer gear-   110 flywheel-   111 symmetry line

1. An engine-mounted autonomous flying device comprising: a main rotorthat gives main thrust to a fuselage; a sub rotor that controlsorientation of the fuselage; an engine that generates energy forrotating the main rotor and the sub rotor; and an arithmetic controldevice that controls rotation of the sub rotor, wherein the main rotoris rotated by being drivingly connected to the engine, the sub rotor isrotated by a motor driven by electric power generated from a generatoroperated by the engine, and when orientation control to tilt thefuselage is performed, the arithmetic control device increases an outputdistribution ratio of the sub rotor to above an output distributionratio of the sub rotor when hovering is performed.
 2. The engine-mountedautonomous flying device according to claim 1, wherein the arithmeticcontrol device sets the output distribution ratio of the sub rotor at10% or more and 30% or less when the orientation control is performed.3. The engine-mounted autonomous flying device according to claim 1,further comprising: an electric power converter that converts theelectric power generated from the generator; and a capacitor that storeselectric power outputted from the electric power converter, wherein thearithmetic control device charges the capacitor when the hovering isperformed, and supplies electric power discharged by the capacitor tothe motor when the orientation control is performed.
 4. Theengine-mounted autonomous flying device according to claim 3, wherein arotational speed of the engine when the hovering is perfomied and arotational speed of the engine when the orientation control is performedare substantially same.
 5. The engine-mounted autonomous flying deviceaccording to claim 1, wherein the engine and the main rotor aredrivingly connected via a belt.
 6. The engine-mounted autonomous flyingdevice according to claim 1, wherein the engine has a first engine parthaving a first piston that reciprocates and a second engine part havinga second piston that reciprocates while facing the first piston.
 7. Theengine-mounted autonomous flying device according to claim 6, whereinthe first piston and the second piston reciprocate inside a continuouscylinder.
 8. The engine-mounted autonomous flying device according toclaim 6, wherein the first piston reciprocates inside a first cylinder,and the second piston reciprocates inside a second cylinder formed as aseparate body from the first cylinder.
 9. The engine-mounted autonomousflying device according to claim 1, wherein the sub rotor is attached toa tip side of a sub arm extending, outward from a portion where theengine is arranged, and the main rotor is attached to a tip side of amain aim being longer than the sub arm and extending outward from theportion where the engine is arranged.
 10. The engine-mounted autonomousflying device according to claim 1, wherein driving force is transmittedto the main rotor via an engine-side pulley attached to a shaftextending from a crankshaft in the engine to an outside, a rotor-sidepulley attached to the main rotor, and a belt looped between theengine-side pulley and the rotor-side pulley.
 11. The engine-mountedautonomous flying device according to claim 1, wherein when a directionin which a first engine part and a second engine part constituting theengine are arrayed is a first direction, and a direction which isperpendicular to the first direction is a second direction, the mainrotor has a first main rotor driven by the first engine part andarranged on an outside along the first direction, and a second mainrotor driven by the second engine part and leveled at a positionopposite the first main rotor, and the sub rotor has on the first mainrotor side, a first sub rotor arranged on the outside along the seconddirection, and the second sub rotor arranged along the second directionat a position opposite the first sub rotor, and on the second main rotorside, a third sub rotor arranged on the outside along the seconddirection, and the fourth sub rotor arranged along the second directionat a position opposite the third sub rotor.
 12. The engine-mountedautonomous flying device according to claim 1, wherein the engine has acrankshaft with a first balance mass formed thereon, and a balancershaft with a second balance mass formed thereon at a symmetric positionrelative to the first balance mass, and the main rotor is rotated bydriving force from the crankshaft aind the balancer shaft.
 13. (ew) Theengine-rirounted autonomous flying device according to claim 2, furthercomprising: an electric power converter that converts the electric powergenerated from the generator; and a capacitor that stores electric poweroutputted from the electric power converter, wherein the arithmeticcontrol device charges the capacitor when the hovering is performed, andsupplies electric power discharged by the capacitor to the motor whenthe orientation control is performed..
 14. The engine-mounted autonomousflying device according to claim 13, wherein a rotational speed of theengine when the hovering is performed and a rotational speed of theengine when the orientation control is performed are substantially same.15. The engine-mounted autonomous flying device according to claim 2,wherein the engine and the main rotor are drivingly connected via abelt.
 16. The engine-mounted autonomous flying device according to claim3, wherein the engine and the main rotor are drivingly connected via abelt.
 17. The engine-mounted autonomous flying device according to claim2, wherein the engine has a first engine part having a first piston thatreciprocates and a second engine part having a second piston thatreciprocates while facing the first piston.
 18. The engine-mountedautonomous flying device according to claim 3, wherein the engine has afirst engine part having a first piston that reciprocates and a secondengine part having a second piston that reciprocates while facing thefirst piston.
 19. The engine-mounted autonomous flying device accordingto claim 4, wherein the engine has a first engine part having a firstpiston that reciprocates and a second engine part having a second pistonthat reciprocates while facing the first piston.
 20. The engine-mountedautonomous flying device according to claim 5, wherein the engine has afirst engine part having a first piston that reciprocates and a secondengine part having a second piston that reciprocates while facing thefirst piston.